[cybmole]

i switched from 650 to t3 & have to say I did not ntoice any difference in line spacing. Have you checked that there is no explicit spacing in your test book.
T3 has about 7 fonts built in, though I only really like the original one.
Some retail/library books will not switch font though, unless you tweak them to remove specific embedded settings.

you could do what you want with the 650 but only if you installed the custom prs+ firmware. I am pretty sure the sony firmware did not allow any of those extras.

There is no custom firmware for T3, not yet anyway, so if those things are important to you ( and you don't want to have to DIY tweak each book) then another make of device could be the way to go.

hyphenation can be fixed, book by book - see my other threads